The present invention relates to a steering lock apparatus of the type that a lock bar moving along the guide section of a lock body is protruded toward the steering shaft for locking.
A conventional steering lock apparatus of this type is designed that the steering lock apparatus has a lock body which is coupled to the steering column of an automobile. The lock body is made up of a cylindrical body section which accommodates a key cylinder which is turned with the key, and a cylindrical guide section which is protruded from the body section toward the steering shaft.
A cam member is provided behind the key cylinder, so that it is turned by the key cylinder. The guide section has a lock stopper in the form of a frame which surrounds the cam member and is urged toward the steering shaft by a spring, and a lock bar one end portion of which is engaged with the lock stopper.
When the key cylinder is set at a locking position, the end portion of the lock bar is protruded toward the steering shaft to lock the steering shaft; i.e., to prevent the rotation of the steering shaft. When the key cylinder is turned from the locking position to an operating position, the cam member operates to move the lock stopper and the lock bar away from the steering shaft, so that the lock bar is disengaged from the steering shaft.
The conventional steering lock apparatus thus designed suffers from the following problem:
For instance, when the automobile equipped with the conventional steering lock apparatus is braked suddenly, the operator's knee may receive a great impact striking the guide section of the lock body hard.
There have been proposed a variety of means for decreasing the impact force which may be applied to the operator's knee in such a case. In one of the means, the guide section of the lock body is so designed that it is broken when an impact force greater than a predetermined value is applied thereto. That is, the guide section is broken to decrease the impact force.
However, the means gives rise to another problem. That is, when the guide section is broken, the lock bar is disengaged from the lock stopper, so that it is moved toward the steering shaft, thus accidentally locking the steering shaft.